Add a chrome://webapks page.

chrome/browser/resources/webapks/about_webapks.js

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+/**
+ * @typedef {{
+ *   shortName: string,
+ *   packageName: string,
+ *   shellApkVersion: number,
+ *   versionCode: number
+ * }}
+ */
+var WebApkInfo;
+
+/**
+ * Creates and returns an element (with |text| as content) assigning it the
+ * |className| class.
+ *
+ * @param {string} text Text to be shown in the span.
+ * @param {string} className Class to be assigned to the new element.
+ * @return {Element} The created element.
+ */
+function createSpanWithTextAndClass(text, className) {
+  var element = createElementWithClassName('span', className);
+  element.textContent = text;
+  return element;
+}
+
+/**
+ * Callback from the backend with the information of a WebAPK to display.
+ * This will be called once for each WebAPK available on the device and each
+ * one will be appended at the end of the other.
+ *
+ * @param {!Array<WebApkInfo>} webApkList List of objects with information about
+ * WebAPKs installed.
+ */
+function returnWebApksInfo(webApkList) {
+  for (let webApkInfo of webApkList) {
+    addWebApk(webApkInfo);
+  }
+}
+
+/**
+ * Adds a new entry to the page with the information of a WebAPK.
+ *
+ * @param {WebApkInfo} webApkInfo Information about an installed WebAPK.
+ */
+function addWebApk(webApkInfo) {
+  var webApkList = $('webapk-list');
+
+  webApkList.appendChild(
+      createSpanWithTextAndClass(webApkInfo.shortName, 'app-name'));
+
+  webApkList.appendChild(
+      createSpanWithTextAndClass('Package name: ', 'app-property-label'));
+  webApkList.appendChild(document.createTextNode(webApkInfo.packageName));
+
+  webApkList.appendChild(document.createElement('br'));
+  webApkList.appendChild(createSpanWithTextAndClass(
+      'Shell APK version: ', 'app-property-label'));
+  webApkList.appendChild(document.createTextNode(webApkInfo.shellApkVersion));
+
+  webApkList.appendChild(document.createElement('br'));
+  webApkList.appendChild(
+      createSpanWithTextAndClass('Version code: ', 'app-property-label'));
+  webApkList.appendChild(document.createTextNode(webApkInfo.versionCode));
+}
+
+document.addEventListener('DOMContentLoaded', function() {
+  chrome.send('requestWebApksInfo');
+});